1. Field of the Invention
The present invention relates to a drug solution transferring device, and particularly to a drug solution transferring device for transferring a toxic drug solution.
2. Description of the Background Art
In a medical institution such as a hospital, conventionally, a dry preparation such as a powdery drug or a freeze-dried drug, which is held in a drug container such as a vial, is dissolved in a solvent for use, and a resultant drug solution is used as an infusion for drip injection. Such a drug will lose its efficacy when it is kept in a state of a drug solution and, consequently, can not be stored in the state of the drug solution. An injection syringe filled with the solvent is connected to the drug container to inject the solvent into the drug container so that the dry preparation in the drug container is dissolved.
In process of dissolving and preparing a toxic drug such as anti-cancer drug, an injection syringe may be removed in such a state that a pressure is applied to a connection portion of the injection syringe or a hydraulic pressure in the infusion container is applied thereto. In this case, a splash or spill of the drug solution may occur at the connection portion even when the pressure is small. When the toxic drug splashes or spills, or when it dries thereafter, an aerosol generates and floats so that the toxic drug is exposed in an ambient environment for a long period of time, resulting in a problem that the toxic drug may exert an adverse influence on health of medical staffs and patients.
Accordingly, there has been proposed a drug solution preparing kit that does not cause the liquid leakage such as a splash and dispersion of an aerosol during preparation of a drug solution (e.g., International Publication No. WO2007/148708).
According to the drug solution preparing kit in International Publication No. WO2007/148708, when a drug that is already prepared is drawn into a barrel and then the barrel is separated from the transfusing tool, a sealing member provided at an end opening of the barrel closes to prevent leakage of the prepared drug. When the prepared drug solution is drawn into the barrel, the pressure in the system becomes lower than an ambient pressure. Therefore, even when a splash or aerosol spouts, the splash or the aerosol occurs inside the vial, and are prevented from external dispersing from the system.
According to the drug solution preparing kit in International Publication No. WO2007/148708, a vial is attached to a vial attaching unit of a transfusing tool, and a first needle covered with a covering member is stuck into an elastic film of the barrel to attach the barrel to the barrel attaching unit. In this state, the drug is dissolved and prepared in the vial, and subsequently a nominal volume of drug solution is drawn into the barrel. Then, the transfusing tool is removed from the barrel.
When the first needle is pulled out from the elastic film of the barrel, a residual toxic drug adhering to the first needle may adhere to a portion near a tip end of the covering member. The toxic drug adhering to the covering member may change into an aerosol. The aerosol thus generated floats, and is partially dried during floating to change into smaller particles of a high drug concentration. This results in a problem that the medical staffs and the patients are exposed to the toxic drug.